Field of the Invention
The present invention relates to video and audio playback technologies.
Description of the Related Art
There exist technologies for capturing video data with a high frame rate and performing slow-motion playback of video. With such slow-motion playback, the frequency of the audio shifts to a low range when the waveform of the audio signal is extended to conform to slow-motion playback, and this can leave viewers with a sense of incongruity. To address this, Japanese Patent Laid-Open No. 2017-009663 discloses a technology for reducing the sense of incongruity by also obtaining audio recording data with a high sampling rate to generate audio data with little sense of incongruity, and by, furthermore, repeatedly playing back this audio data to reduce silent intervals. Also, Japanese Patent Laid-Open No. 2017-009663 discloses reducing the volume level every repetition, at the time of repetitive playback of audio.
The technique of Japanese Patent Laid-Open No. 2017-009663 reduces the volume level gradually after the video has switched to variable speed playback, and thus the volume level does not change immediately when the video expression is changed. Since there is thus no change in the audio expression when switching from normal playback to variable speed playback such as slow-motion playback or stop-motion playback, viewers can be left with a sense of incongruity.